Structure of Two Crystal Modifications of Cu(II) trans-Bis-(1,1,1-trifluoro-4-iminopentan-2-onate)

Two crystal modifications of the volatile Cu(II) complex prepared from fluorinated -ketoimine (1,1,1-trifluoro-4-iminopentanon-2-one), CH₃(NH)CCH₂COCF₃, were studied by X-ray crystallography (CAD-4 Enraf-Nonius automatic diffractometer, MoK radiation, graphite monochromator). The phases have molecular structures consisting of trans complexes. In both cases, the square plane around the Cu atom is completed to a tetragonal bipyramid by the carbon atoms of the chelate rings of the neighboring complexes; the Cu...C distance equals 3.36-3.39 . For Cu–O and Cu–N distances, an anomalously large difference between the centrosymmetric and noncentrosymmetric complexes has been found.